A chassis assembly is used in various environments. For example, a chassis can be used as an indoor enclosure or an outdoor enclosure on a utility pole, on the outside of building, in a vault underground, etc. In order to protect circuitry inside the chassis, the chassis needs to be sealed against elements in the environment, such as dust, corrosive airborne contaminates, or water. Furthermore, some chassis support modules often are coupled to the chassis. These chassis, therefore, use openings or windows to allow access to the interior of the chassis. These windows or openings also need to be sealed against elements in the environment.
Although current casting and machining technology enables the construction of chassis which meet the above criteria, it is desirable to reduce the costs and complexity of the chassis. For example, machining a chassis is significantly more expensive than casting. However, current casting techniques have other limitations, such as the ability to only cast a window in one wall of the chassis.